Dada Gottelli

Molecular genetics of the most endangered canid: the Ethiopian wolf Canis simensis

The worlds most endangered canid is the Ethiopian wolf Canis simensis, which is found in six isolated areas of the Ethiopian highlands with a total population of no more than 500 individuals. Ethiopian wolf populations are declining due to habitat loss and extermination by humans. Moreover, in at least one population, Ethiopian wolves are sympatric with domestic dogs, which may hybridize with them, compete for food, and act as disease vectors. Using molecular techniques, we address four questions concerning Ethiopian wolves that have conservation implications. First, we determine the relationships of Ethiopian wolves to other wolf‐like canids by phylogenetic analysis of 2001 base pairs of mitochondrial DNA (mtDNA) sequence. Our results suggest that the Ethiopian wolf is a distinct species more closely related to gray wolves and coyotes than to any African canid. The mtDNA sequence similarity with gray wolves implies that the Ethiopian wolf may hybridize with domestic dogs, a recent derivative of the gray wolf. We examine this possibility through mtDNA restriction fragment analysis and analysis of nine microsatellite loci in populations of Ethiopian wolves. The results imply that hybridization has occurred between female Ethiopian wolves and male domestic dogs in one population. Finally, we assess levels of variability within and between two Ethiopian wolf populations. Although these closely situated populations are not differentiated, the level of variability in both is low, suggesting long‐term effective population sizes of less than a few hundred individuals. We recommend immediate captive breeding of Ethiopian wolves to protect their gene pool from dilution and further loss of genetic variability.

Male philopatry, extra-pack copulations and inbreeding avoidance in Ethiopian wolves (Canis simensis)

Abstract Monogamous pairings have been regarded as the fundamental social unit in all canid species, including those living in packs. In Ethiopian wolves, however, habitat saturation limits dispersal, which raises the question of whether they avoid inbreeding and, if so, by what mechanism. In two study areas Ethiopian wolf packs had stable memberships. Each pack comprised two to eight adult males, one to three adult females, including a clear-cut dominant individual of each sex, together with one to six yearlings and up to six pups (nu2005=u20059 packs). Males remained in their natal packs, apparently throughout their lives. Some females also failed to disperse while others dispersed in their second or third year and became floaters. Dominant females monopolized breeding, and were succeeded either by their most dominant daughters (three cases) or by floaters (two cases). In the former case there is potential for incest; however, 70% of 30 copulations observed were between the dominant female of one pack and a male from an adjoining pack. In Ethiopian wolves, under conditions where dispersal is constrained and the potential for inbreeding is high, extra-pack matings (and associated multiple paternity) result in outbreeding. We raise the possibility that extra-pair copulations may be widespread in canid societies and that the monogamy supposedly fundamental to the family may be more sociological than genetic.

Diet and Feeding Behavior of Ethiopian Wolves (Canis simensis)

The Ethiopian wolf ( Canis simensis ) is a rare and endangered carnivore found in only a few mountain ranges of the Ethiopian highlands. We studied its diet and feeding behavior in Bale Mountains National Park, Ethiopia, from 1988 through 1992. Observations of foraging behavior ( n = 380) and scat analysis ( n = 689) suggested that the Ethiopian wolf specializes in eating rodents. Rodents accounted for 96% of the prey occurrences and 97% volume in the droppings. The giant molerat ( Tachyoryctes macrocephalus ) was the main food item, followed in importance by three species of rats ( Arvicanthis blicki, Lophuromys melanonyx , and Otomys typus ). Ethiopian wolves foraged solitarily throughout the day, but occasionally small packs (≤6) hunted hares, young antelopes, and sheep. During food-choice experiments, wolves significantly preferred Tachyoryctes to Arvicanthis and Lophuromys , Arvicanthis to Lophuromys , and either of them to Stenocephalemys , which was invariably discarded. Lepus starcki was preferred to any of the species of rats. The contribution of different species of prey to the diet of the Ethiopian wolf correlated with abundance of prey.

The effect of the last glacial age on speciation and population genetic structure of the endangered Ethiopian wolf ( Canis simensis )

During the last glacial age, Afro‐alpine habitats were widespread across the highlands of Ethiopia. A wolf‐like canid ancestor is thought to have colonized this expanding habitat and given rise to a new species that was remarkably well adapted to the high altitude environment: the Ethiopian wolf Canis simensis. Here, we address the timing of genetic divergence and examine population genetic history and structure by investigating the distribution of mitochondrial DNA (mtDNA) sequence variation. The pattern of mtDNA variation and geographical distribution indicate an initial population expansion, probably immediately after divergence from the wolf‐like ancestor, around 100 000 years ago. The partition of mtDNA haplotypes that followed was most likely the result of habitat reduction and fragmentation at the onset of deglaciation ~ 15 000 years ago. Phylogenetic and geographical associations suggest that the most likely genetic partitioning corresponds to three mountain areas, Arsi/Bale, Wollo/Shoa and Simien/Mt. Guna. Although there is a degree of clustering of haplotypes from both sides of the Rift Valley, the lack of reciprocal monophyly does not support the taxonomic classification of two subspecies. This study highlights the importance of populations north of the Rift Valley for the maintenance of genetic variability within the species and has consequent implications for conservation.

Genetic analysis reveals promiscuity among female cheetahs

Cheetahs (Acinonyx jubatus) have a combination of ranging patterns and social system that is unique in mammals, whereby male coalitions occupy small territories less than 10% of the home range of solitary females. This study uses non-invasive genetic sampling of a long-term study population of cheetah in the Serengeti National Park in Tanzania to infer the mating system. Individual cheetah genotypes at up to 13 microsatellite loci were obtained from 171 faecal samples. A statistical method was adapted to partition the cubs within each litter (n=47) into full-sibling clusters and to infer the father of each cluster using these loci. Our data showed a high rate of multiple paternity in the population; 43% of litters with more than one cub were fathered by more than one male. The results also demonstrated that female fidelity was low, and provided some evidence that females chose to mate with unrelated males within an oestrus cycle. The low rate of paternity assignments indicated that males living outside the study area contributed substantially to the reproduction of the cheetah population.

Range expansion and hybridization in Round Island petrels (Pterodroma spp.): evidence from microsatellite genotypes

Historical records suggest that the petrels of Round Island (near Mauritius, Indian Ocean) represent a recent, long‐distance colonization by species originating from the Atlantic and Pacific Oceans. The majority of petrels on Round Island appear most similar to Pterodroma arminjoniana, a species whose only other breeding locality is Trindade Island in the South Atlantic. Using nine microsatellite loci, patterns of genetic differentiation in petrels from Round and Trindade Islands were analysed. The two populations exhibit low but significant levels of differentiation in allele frequencies and estimates of migration rate between islands using genetic data are also low, supporting the hypothesis that these populations have recently separated but are now isolated from one another. A second population of petrels, most similar in appearance to the Pacific species P. neglecta, is also present on Round Island and observations suggest that the two petrel species are hybridizing. Vocalizations recorded on the island also suggest that hybrid birds may be present within the population. Data from microsatellite genotypes support this hypothesis and indicate that there may have been many generations of hybridization and back‐crossing between P. arminjoniana and P. neglecta on Round Island. Our results provide an insight into the processes of dispersal and the consequences of secondary contact in Procellariiformes.

Genetic analysis of scat reveals leopard Panthera pardus and cheetah Acinonyx jubatus in southern Algeria

Assessing the biodiversity of a region, particularly when it includes rare, cryptic and nocturnal species, is notoriously difficult but nevertheless of great importance, especially in regions that have received little prior research interest. Species in these regions are often only perceived to be present through the identification of animal signs such as scat or hair. Here we show how molecular techniques can be used to sequence mitochondrial DNA extracted from the scat of essentially unknown carnivore species and thus assess the species present in a remote desert region in southern Algeria. In doing so we present a reliable and reproducible method for determining carnivore biodiversity through non-invasive sampling. We also identify two species of large carnivore in an area where one, the cheetah Acinonyx jubatus , is known to exist but at very low densities, and another, the leopard Panthera pardus , has never previously been observed.

Assessing current genetic status of the Hainan gibbon using historical and demographic baselines: implications for conservation management of species of extreme rarity.

Evidence‐based conservation planning is crucial for informing management decisions for species of extreme rarity, but collection of robust data on genetic status or other parameters can be extremely challenging for such species. The Hainan gibbon, possibly the worlds rarest mammal, consists of a single population of ~25 individuals restricted to one protected area on Hainan Island, China, and has persisted for over 30 years at exceptionally low population size. Analysis of genotypes at 11 microsatellite loci from faecal samples for 36% of the current global population and tissue samples from 62% of existing historical museum specimens demonstrates limited current genetic diversity (Na = 2.27, Ar = 2.24, He = 0.43); diversity has declined since the 19th century and even further within the last 30 years, representing declines of ~30% from historical levels (Na = 3.36, Ar = 3.29, He = 0.63). Significant differentiation is seen between current and historical samples (FST = 0.156, P = 0.0315), and the current population exhibits extremely small Ne (current Ne = 2.16). There is evidence for both a recent population bottleneck and an earlier bottleneck, with population size already reasonably low by the late 19th century (historical Ne = 1162.96). Individuals in the current population are related at the level of half‐ to full‐siblings between social groups, and full‐siblings or parent–offspring within a social group, suggesting that inbreeding is likely to increase in the future. The species current reduced genetic diversity must be considered during conservation planning, particularly for expectations of likely population recovery, indicating that intensive, carefully planned management is essential.